Automobile master brake cylinder tool



Jan. 9, M` EDAWS 2,537,515

AUTOMOBILE MASTER BRAKE CYLINDER TOOL Filed Sept. 27, 1948 gmc/nm MAR/0NE. DA V/ ATTORNEYS Patented Jan. 9, 19,51

AUroMoniLE MASTERBRAKE cYmNDER Marion Elbert Davis, Jacksonville, Fla.

lamination september' 27, 194s, serial No. 51,362

(ci. l12x-1) This invention relates to handtools, and more particularlyto tools ofthe trip hammer type for operation in confined areas notreadily accessible to tools of ordinary nature, and is particularlyadapted for removing burrs from the edge ofthe brake release hole ofautomobile hydraulic master brake cylinders.

In the type of hydraulic brakes now in common 11 Claims.

dles of the tool, a hammer will be cocked and tripped yto deliver a blowagainst the anvil. V

Although the tool will be described in connection with use for removingburrs from the edge of the release hole of automobile hydraulic masterbrake cylinders, it will be understood that this is merely by way ofexample, and that the f tool is capable `of a great many other uses.

usage on automobiles, the master brake cylinder l has a small holethrough which fluid passes when the Abrakes are released. Uponapplication of the brakes, a rubber cup passes this hole and if the edgeof the hole is sharp it cuts a groove inthe rubber cup reducing theeiiiciency of the brakes. In order to avoid this, the edge of the holemust be smoothed by beveling or rounding. As the hole is in the interiorof the master cylinder casting, it is impossible to reach it withordinary tools to bevel or round the edge.

The object of the present invention is to provide l' a tool which can beinserted in coninedareas and operated from without tov deliver a' hammerblow to an anvilor other-device carried bythe tool within the confinedarea. 1 y

A more Vspecific object ofthe invention is top rovide aA tool of thisnature in'which the tool is of vthepliers type for one-hand operationand'the hammer isconnected'to the handles by a toggle-i like connectionso that considerable force may be stored up for moving the'hammer beforethe I toggle is broken.

Other objects of the invention will become-apparent vfrom the followingvdescription of one practical embodiment thereof when taken inconjunction with the drawings which` accompany and form a part of thisspecication.

In the drawings:

Figure l is a longitudinal section through a tool constructed inaccordance withA the presentinvention, and a portion of an automobile,hydraulic master brake cylinder, being shown in released position;

Figure 2 is a section similar to Figure 1 with the hammer in cockedposition;

Figure 3 isa transverse section vtaken on the line 3-.3 of Figure 2;and,

Figure 4 is an enlarged sectional view vof one end of one arm of thetool showing the mounting of the anvil and its relationship to thecylinder rrelease hole upon which it is to operate. In general, thepresent invention comprises a pliers-type ytool which can be operatedbyV one hand by inserting the end of the tool, into a restricted areaand placing the ,anvil -against the part to be operated upon. Bysqueezing the hanthe hammer of the tool.

Referring to the drawings in detail, the tool comprises av pair of armsi and 2 which are joinedA together Athrough the medium of a hammer 3.Both arms i and 2 are shown as of channei con-l struction, arm l beingstraight from end to end,

and arm 2 being bent near its middle to provide fory the movement'necessary to operatethe tool, as Will be described.

The hammer 3 is an elongated bar, shorter than the arms l and 2, andrectangular in cross'- section. A hole fi, transversely through the bar,is provided at the inner end of the hammer, and a second hole 5 isprovided, longitudinally spaced from the holed. Apivot pin 6 passesthrough openings in the side `webs of arm l and through the :holed inthehammer to pivotally connect the hammer to the arm, and a pin 'i connectsthe hammer to the side webs ofthe arm 2. Thus thev hammer is pivotallyconnected toboth arms, and forms a connecting link between the arms.

VA spring 8 is positioned lbetween the handle portions of the arms I and2 to Vhold theseportions of the arms in normally spread apart position.The spring has a central coil and extending legs bearing against theinner sides of the channeled arms. ofthe spring may be attached to itsarm to retain vthe spring in position. j nAt its far or hammer end, arm2 carries a spring retainingclip 9, which is right angular and has itsbase riveted or otherwise secured to the bottom web of the channel. lts`upstanding portion is in 'such position as to be substantially iiushwith the end of the hammer when the hammer is in cocked position withinthe arm 2; Hammer 3 is provided with a transverse groove I0 in its endface, and the upstanding portion of the retaining clip 9 is bent to forma matching ridgev l l to seat in the groove l0 to hold the hammer incocked position.

Near the opposite end from the handle portion ,of arm l there lis a holel2 through the upper web of the channel to permit the head of anvil i3to projectinto the inside of the arm where it can be struck by thehammer. Anvil I3 is supported upon the free end of a leaf spring itlwhich has its'opposite end riveted or otherwise secured to Either one orboth of the legs causing the arms to separate. This outward pressuremoves the hammer pivots 6 and l in opposite directions causing hammer 3to move about its pivots into the channel of arm 2 .until groove lllengages ridge ii in the retaining clip 9. The

hammer is then in cocked position, and it will be seen that due to theaction oi spring' this the normal or inoperative position of the tool.When it is desired to bevel or round the edge of a brake cylinderrelease hole, the tool is picked up by the handle portions of the arms Iand 2 and the opposite end of the tool inserted into the casing of thebrake cylinder. It will be noted from Figure l that the release hole i5is a substantial distance within the casing and that the passage withwhich Athe hole communicates is too small for the use of ordinary tools.As mentioned above, the endof the tool is slipped intovthe casing untilthe anvil is in alignment with the release hole whereupon the tool ismoved to insert the pointed end of the anvil into the hole. With theanvil held rmly seated against the rim of the hole, the handles of thetool are squeezed together. As the hammer is latched to the arm l, pivot'l is inoperative, and arm 2 and hammer 3 swing about pivot spreadingthe jaws of the tool and moving the hammer away from the anvil. When arm2 strikes the cylinder casing. wall, as shown in Figure 1, there can beno further separating of the jaws as the anvil is in engagement with therelease holerim. As pressure on the handles is built up the forcetendingtorotate the hammer around its pivot ,7 is increased, which forceis initially overcome by the holdingpcwer of clip 9. When the force issuiiicient, hammer 3 will snap free from clip S and, swinging .aboutboth pivots 6 and?, will fly against the`V head of the anvil deliveringan impact whchis transmitted to the rim of the releaseholewith which thebeveled face of the anvil is in contact. The resilient mounting of theanvil will ensure the beveled portion Aof the anvil striking flushagainst the hole rim, even though the tool and consequently the anvil,may be moved slightly by the sudden release of the hammer. As soon aspressure is released uponvthehandles, spring 8 causes the hammer to bere-cocked. Thus by squeezing and releasing the handles as many blows maybe struck against the anvil as is necessary without removing the toolfrom thebrake cylinder casing.

While in the above one practical embodiment of the invention has beendescribed, it will be understood that the structure may depart from theprecise embodiment shown and described within the scope of the inventionasV defined in the appended claims.

What is claimedis:

l. A hand tool comprising, a pair of arms, a hammer pivotally connectedtoezich ofsaid arms, said pivotal connections betweensaid hammer andsaid arms being near one end of said hammer and spaced apartlongitudinally of said hammer, and a latchcarried by one of said. armsto ree easably engage the free end of said hammer.

2. A hand tool comprising, a. pair of arms, a

hammer pivotally connected to each of said arms, the pivotal connectionsbetween said hammer and said arms being near one end of said hammer andspaced apart longitudinally of said hammer, a latch carried by one ofsaid arms to releasably engage the free end of said hammer, and a springbetween said arms to normally hold said arms apart and said hammer inengagement with said latch.

3. A hand tool comprising, a pair of arms, a hammer pivotally connectedto each of said arms, the pivotal connections between said hammer andsaid arms being near one end of said hammer and spaced apartlongitudinally of said hammer, and an anvil carried by one of said armsin position to be struckzby said hammer when said arms are moved towardone another.

4; A hand tool comprising, a pair of arms, a hammerpivotally connectedto each of said arms, the pivotal connections between said hammer andsaid arms being near one end of said hammer and spaced apartlongitudinally of said hammer, a latch carried by one of said arms toreleasably engage the free end of said hammer, and an anvil carried bythe other of said arms in position to be struck by said hammer whensaid. arms are urged toward one another with sufficient .force toovercome the holding power of said latch.

5. A hand tool comprising, a pair of arms, .a hammer pivotally connectedto each of said arms, the pivotal connections between said hammer andsaid arms being near oneend of said hammer and spaced apartlongitudinally of said hammer, a latch carried by one of said arms torelcasably engage-the free endof said hammer, an anvil carried by theother of said arms in position to be struck by said hammer when saidarms are urged toward one another with sufficient force to overcome theholding power of said latch, and a springv between said arms to normallyhold said arms apart and said hammer in engagementwith said latch.

6. .A hand .tool comprising, a pair of arms. and a, hammer, said hammerhaving one end pivotally connected. toone f of saidarms at a mid-pointthereoiand'a pivotal connection to a mid-point on the other of-said armsat a pointspaced lon-l gitudinally of said hammer from Vsaid end pivot,whereby movement of the arms toward one ane' other. will cause thehammer to swing relative to the arms.

7, A hand tool comprising, a pairof arms, a hammerhaving onelendpivotally connected to a mid-point on one of said arms and a pivotalconnection to a mid-point on. the. other said arm at a point spacedlongitudinally of .said vhaine mer from said end pivot, wherebymovementof the arms toward. one anotherv will cause the hammer .to swingrelative to the arms, and a latch carried near one end of one of Vsaidarms to re; leasably engage the free end of saidhammer to hold saidhammerto said arm until said arms' are urged .to one another withsufficient force to overcome the holding power ofv said latch.

, 8. A handtool. comprising, a pair of arms, 'a hammer having one endpivotally connected to a mid-point on one of said arms and a pivotalconection to a mid-point on the other said arm ata point spaced'longitudinally of said hammei` from said end pivot, whereby movement`ofjtlfie arms toward one another will cause the hammer to .swingrelative to the arms, a latch carried near` one end. of one of saidarmsto releasably engage the free end lof said hammer to hold said hammer tosaid arm until saidarms are urged toward one another with sufficientforce to overcome the holding power of said latch, and a spring betweensaid arms at the opposite end of said arms from said latch normally tohold said` arms apart and said hammer in engagement with said latch.

9. A hand tool comprising, a pair of arms, a hammer having Yone endpivotally connected to a mid-point on one of said arms and a pivotalconnection to a mid-point on the other of said arms at a point spacedlongitudinally of said hammer from said end pivot, whereby movement ofsaid arms toward one another will cause said hammer to swing relative tothe arms, a, latch carried near the end of one of said arms toreleasably engage the free end of said hammer to hold said hammer tosaid arm until the arms are urged toward one another With suicient forceto overcome the holding power of said latch, an anvil mounted near theend of the other of said arms in position to be struck by said hammerwhen released from said latch, and a spring be tween said arms at theopposite ends from said latch and said anvil to hold said arms apart andsaid hammer in engagement with said latch.

10. In a tool as claimed in claim 9, said anvil having a pointed end forentrance into an opening to be beveled and an annular tapering shouldertherebeneath.

11. In a tool as claimed in claim 9, said anvil having a pointed end forentrance into an opening to be beveled and an annular tapering shouldertherebeneath, said anvil being secured to the free end of a resilientmember having its other end xed to one of said arms.

MARION ELBERT DAVIS.

REFERENCES VCITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,367,238 Coakley Feb. 1, 19211,927,097 Meyering Sept. 19, 1933

